In an effort to modernize residential, commercial and industrial buildings, lighting, heating and various other systems are being installed with multiple sensors capable of communicating with a central controller in response to a predetermine command. For example, smart controls are being installed in homes to manage energy utilization. This is achieved by controlling for example, heating, air conditioning and ventilation systems using a single controller. The control of these systems is done using a number of transducers located around the house to permit the controller to properly manage the systems in an efficient manner.
Generally, the various components of these systems are connected to the controller using wires pre-installed during construction of the house or sometime thereafter. Obviously, there are limitations associated with wiring a house after it is built. This can create problems when the components need to be moved or re-located. Some systems will utilize existing house 120VAC wiring to control devices at a number of locations in the house. For example, to turn lamps on and off.
Wireless systems are now available which utilize low power communication to control remotely located components. However, most of these are only able to offer unidirectional communication because of the costs involved in providing a reverse channel. This cost is a result of the need to provide duplicate components for the transmitter and receiver sections of the transducer.
Normally, a transceiver makes use of a transmitter and a receiver circuit and a switch or duplexer connecting the transmitter and receiver circuit to an antenna for transmission or reception of a signal. The transmitter and receiver each includes input and output filters. These filters and the duplexer are generally passive elements which are relatively costly to assemble.
Efforts have been made to reduce the number of components to facilitate integration. For example, U.S. Pat. No. 5,355,524 which issued to Higgins teaches a radio design architecture which facilitates integration by elimination of certain filtering elements. However, Higgins' circuit design still requires the use of a Transmit/Receive switch 208 or duplexer to switch the transceiver from a receive mode to a transmit mode and vice-versa.
A need therefore exists for a transceiver circuit design which further reduces the number of components while remaining suitable for integration as an integrated circuit.
Accordingly, it is an object of the present invention to provide a radio transceiver which is designed such that the transmitter and receiver sections of the transceiver share a number of components.
Another object of the present invention, is to provide a radio transceiver which is designed to facilitate monolithic integration of its components.
In accordance with another object of the present invention, there is provided a radio transceiver which is designed to reduce the number of components and manufacturing costs while offering bi-directional communication.
According to an aspect of the present invention, there is provided a radio transceiver having a receive mode and a transmit mode, said radio transceiver comprising:
transmitter means having an output thereof for connection to an antenna circuit to transmit a signal when said radio transceiver is in a transmit mode; PA1 receiver means having an input thereof for connection to said antenna circuit to receive a signal when said radio transceiver is in a receive mode; PA1 first means for activating and de-activating said transmitter means; PA1 second means for activating and de-activating said receiver means; and PA1 control means connected to said first and second activating and de-activating means such that when said radio transceiver is in said receive mode, said first means, responsive to said control means, de-activates said transmitter means and said second means, responsive to said control means, activates said receiver means and when said radio transceiver is in said transmit mode, said first means responsive to said control means activates said transmitter means and said second means, responsive to said control means de-activates said receiver means.